A390507 a(n) = number of 1's in A390505(n).

1, 2, 1, 3, 3, 2, 2, 3, 4, 3, 3, 5, 3, 3, 1, 4, 4, 3, 4, 6, 4, 4, 4, 5, 6, 5, 3, 5, 4, 2, 2, 3, 5, 4, 4, 6, 4, 4, 5, 6, 7, 6, 4, 6, 5, 3, 3, 6, 6, 5, 6, 8, 6, 6, 4, 5, 6, 5, 4, 6, 3, 3, 2, 4, 4, 3, 5, 7, 5, 5, 5, 6, 7, 6, 4, 6, 5, 3, 4, 7, 7, 6, 7, 9, 7, 7

Offset

1,2

Links

Table of n, a(n) for n=1..86.

Formula

a(n) = A007953(A390505(n)).

Example

A390505(20) = 10111011, so a(2) = 6.

Mathematica

f[w_] := StringJoin[Map[IntegerString[Length[#], 2] <> ToString[#[[1]]] &, Split[Characters[w]]]];
s[n_] := Map[StringJoin[Map[ToString, Rest[IntegerDigits[#, 2]]]] &, Range[2, 2^(n + 1) - 1]];
m = Map[f, s[6]]   (* A390505 *)
m1 = ToExpression /@ Characters /@ m; u = Map[Length, m1]
Table[Count[m1[[n]], 1], {n, 1, 120}]  (* A390507 *)
(* Peter J. C. Moses, Nov 05 2025 *)

Crossrefs

Cf. A007953, A390505, A390506.

Sequence in context: A198790 A306995 A212907 * A308584 A046819 A159945

Adjacent sequences: A390504 A390505 A390506 * A390508 A390509 A390510

Keyword

nonn,base

Author

Clark Kimberling, Dec 02 2025

Status

approved